I am facing a persistent MQTT issue with my Teltonika device, and I would like your help in diagnosing it.
Below are all the technical details of my setup.
Device Information
Device Model: (FMC003)
MQTT Server Information
Broker: EMQX 5.8.8 (installed on Ubuntu 22.04)
Anonymous Auth: Enabled
Listeners Enabled:
TCP port 1883
Server Logs (EMQX Log showing the problem)
2025-12-14T12:24:42.393122+03:00 [debug] tag: SOCKET, msg: emqx_connection_terminated, peername: 151.254.95.180:8483, reason: {shutdown,tcp_closed}
2025-12-14T12:24:42.393373+03:00 [info] msg: terminate, peername: 151.254.95.180:8483, reason: {shutdown,tcp_closed}
2025-12-14T12:24:53.363738+03:00 [debug] tag: SOCKET, msg: emqx_connection_terminated, peername: 151.254.95.180:3411, reason: {shutdown,tcp_closed}
2025-12-14T12:24:53.363973+03:00 [info] msg: terminate, peername: 151.254.95.180:3411, reason: {shutdown,tcp_closed}
What I Have Already Verified
MQTT broker is reachable from the internet
I can connect successfully using Postman MQTT client without username/password
Ports are open and listening
No rate limit or ACL rules are blocking the device
Device APN is correct
“Use TLS” is disabled (also tested with TLS enabled)
also screen for conf are attached
The disconnects happen every ~10 seconds and no data is published.
I need help understanding whether this is caused by:
Incorrect MQTT configuration on the device
MQTT keepalive mismatch
Required parameters such as DeviceID / Username
Missing Last Will topic
QoS requirements
Something specific to Teltonika MQTT implementation
My Goal
I want the Teltonika device to publish MQTT data continuously to the EMQX server without disconnecting.
Any guidance, documentation, or examples of correct MQTT configuration for Teltonika devices would be greatly appreciated.